Testing method for determining water resistance of wood pellets

This study aimed at developing a simple, quantitative index for measuring the water resistance of wood pellets. Pellets made from various wood raw materials and other plant-based raw materials, as well as torrefied pellets, were used. Two aluminum plates with a size of 50 mm x 60 mm x 10 mm (about 76.6 g) with two dents were prepared. Two samples were laid on the plate in water and were covered with another plate. A displacement meter contacted the plate, and the rise of the plate because of sample swelling was recorded at 10-s intervals until the rise became stable. The effect of the weight of the aluminum plate and displacement meter were not significant. The temporal change in the diameter swelling of pellets was believed to be expressed by the equation developed. The suitable length of samples required for this test was obtained.